In recent years, as an electrically rewritable nonvolatile semiconductor memory device, a resistance-change memory such as a resistive RAM (ReRAM) that uses a variable resistance element as a memory element or a phase-change RAM (PCRAM) that uses a phase-change element as a memory element has been attracting attention as a successor to flash memory.
In the resistance-change memory, since a cell array can be configured by laminating, e.g., a variable resistance element and a rectification element such as a diode at each cross-point of a bit line and a word line, a three-dimensional laminated memory whose memory capacity can be heightened can be formed without increasing an area of a cell array portion.
The resistance-change memory finally has a configuration in which an oxide film is buried between many pillars in which the variable resistance element and the diode are laminated. The variable resistance element is constituted of a variable resistance material/an electrode such as an electrode/a metal oxide (two- or three-dimensional base).
However, in the above-described configuration, an impurity such as fluorine or hydrogen that diffuses into the variable resistance material from the oxide film. It becomes a buried material may possibly degrade characteristics of the variable resistance material. Therefore, a configuration that the diffusion of the impurity, e.g., fluorine or hydrogen is suppressed by covering a side surface of the variable resistance material with a silicon nitride film has been suggested (see, e.g., JP-A 2009-123900 [KOKAI]).
On the other hand, when a silicon nitride film is formed in such a manner that it is in contact with a side surface of a silicon diode as a rectification element, a reverse current increases to degrade rectification element characteristics.